1. Technical Field
The present invention relates to a method for forming a pattern and a method for manufacturing a liquid crystal display.
2. Related Art
Photolithography, for example, is used for manufacturing devices having wiring lines, such as electronic circuits and integrated circuits. In photolithography, a photosensitive material called a resist is coated on a substrate on which a conductive film has been coated so that a circuit pattern is exposed and developed, and then the conductive film is etched corresponding to a resist pattern to form a thin film wiring pattern. However, photolithography needs large-scale equipment such as vacuum apparatuses and cumbersome processes. In addition, almost all of materials are wasted due to a low efficiency of about several percent in using the materials, resulting in high manufacturing costs.
Alternatively, a method is proposed in which a wiring pattern is formed on a substrate using a droplet discharge method (called an inkjet method) in which a liquid material is discharged from a liquid discharge head as a droplet. For example, the method is disclosed in JP-A-2002-72502.
In the method, an ink for forming a wiring pattern is directly coated on the substrate as a pattern. The ink is a functional liquid in which a conductive fine particle such as a metal fine particle or the like is dispersed. Then, heat treatment and laser irradiation are carried out so that the ink is converted into a conductive thin film pattern. This method has a merit that no photolithography is needed, drastically simplifying processes and reducing the amount of raw materials.
When film patterns are formed on a substrate by using an inkjet method, a bank structure called a bank is typically formed in order to prevent ink from spreading. The surface of the bank is subjected to a lyophobic treatment to prevent the bank from ink adhering. In this case, a problem arises in that ink does not smoothly flows in an area surrounded by the bank due to lyophobicity given to the whole bank, lowering the wettability of the ink with respect to the side surface of the bank. In addition, ink is repelled on the side surface of the bank, resulting in a formed film being uneven. Therefore, it is in great demand that wettability is improved in an area that ink is discharged to and is partitioned by the bank.